Method of grinding track rails



Aug. 15, 1933. c. A. FOX 1,923,020

METHOD OF GRINDING TRACK RAILS Filed Oct. 4, 1932 2 Sheets-Sheet 1 03 LI Di E Z6 /Z0 I N 2 M "WW 1 J6 Q) H Z3 VENTOR.

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Au 15, 1933. c A FOX 1,923,020

METHOD OF GRINDING TRACK RAILS Filed Oct. 4, 1932 2 Sheets-Sheet 2 1VENTOR. w/r/vessis 4 BY A TTORNE Y3.

Patented Aug. 15, 1933 i UNITED STATES METHOD OF GRINDING TRACK RAILSCyril A. Fox, Oakmont, Pa.

Application October 4, 1932.

Serial No. 636,153

2 Claims. -(Cl. ESL-J78) My invention pertains tothe grindingofsurfaces, and relates with special importance to methods of grindingtrack rails, such, for instance, as are employed in railroads, streetrail- 5 ways and the like.

Unevennesses in the operating surfaces of track rails constitute asource of material difficulty to the operators of railroads,street-railway lines, etc. Such unevennesses destroy the comfort ofpassengers, produce vibrations which are liable to loosen the iasteningsof freight packages and the like, and reduce the speed at which therolling stock can safely be allowed to travel. The unevennessesoriginally occur because of the wheels of the rolling stock pounding atcertain localized points, owing to special rack conditions obtaining atthese points, and because of the tracks springing downward at certainpoints, owing to the proximity of joints, and as well as for a number ofother reasons. Once an irregularity has developed, not only does it tendto increase, because of the blow given by every wheel which strikes theirregularity, but other irregularities appear beyond the first one, dueto the fact that the wheels jump from the track on striking the firstirregularity andimpart a hammer blow to the track when they returnthereto at a point further along the rail, thereby starting a depressionbeyond the first irregularity. This depression becomes deepened in time,and occasions still another depression beyond it; so that the track intime becomes in eiiect cor-- rugated for quite a distance beyond thefirst r irregularity. In street railways the irregularities generallytake the form of depressions, usually occurring at so-called poundpoints, though sometimes projections occur which have similar badeffects to those which have been mentioned. Such projections arecreated, of course, at newly welded joints, and must be removed. Inrailroads the irregularities most frequently develop at and near therail joints. As one example of this, the trailing end of a rail, at ajoint, will spring downward under the weight of a car wheel, causing animpact or the wheel against the receiving edge of the next rail,followed by a bounding of the wheel from the rail and an impact'at apoint a little further on. The result, after the passage of a materialamount of traffic, is an irregular rail which occasions great discomfortto the passengers.

In the practice of myimproved method, i dispose a peripherally actinggrinding wheel with V5 its axis oblique to the rail, and effect arelative movement between the grinding wheel and the rail to perform thegrinding operation. With the grinding wheel thus obliquely disposed, thebeginning and end of the cut will be oblique to the rail, as also willbe any special depressions caused by such vibrations of the wheel as mayoccur. Supposing now that a car wheel arrives at a place where grindinghas been conducted, the line of the beginning of the grinding cut willbe inclined with respect to the line of engagement of the-rail by thewheel; so that the wheel cannot drop immediately onto any lower surfacethat may occur beyond the beginning 01 the out, but remains upon thehigh part of the rail until it is no longer thus supported, when thewheel will tilt the slight distance necessary for it to ride partly onthe high part of the rail and partly on the slightly lowered part justbeyond the beginning of the cut. Thus there is no possibility of thewheel dropping suddenly into a depression, or pounding in any Way. Where5 the grinding wheel has caused special depressions, because, forinstance, of uncontrollable vertical movements during the grindingoperation, these depressions are inclined to the transverse line inwhich a car wheel engages the rail; so that not only does the aboveefiect occur but often the wheel will ride upon both sides of thedepression at the same time. These v conditions make it possible togrind out a depression with a relatively small longitudinal movement 5of the wheel, since a long slope towards and away from the bottom of thedepression becomes unnecessary. V

A rail surface ground by my improved method "improves, and becomes morelevel, with the passage of traffic thereover, instead of deterioratingand becoming morecorrugated, as is the case with other methods, exceptperhaps where the surface has been specially finished by means ofreciprocating abrasive bricks or the like. The improvement is due to thefact that the wheels gradually work down the little inclined grindingridges (which, of course, are only measurable in thousandths of an inch)until the whole rail top becomes quite smooth and level.

The top of a rail is usually convex, a usual curvature being a twelveinch radius for a rail three inches wide, giving an increase in heightat the center of about one thirty-second of an inch. Accordingly, forgrinding such rails, I the periphery of the grinding wheel of alongitudinal contour such as to correspond with the predetermined curveof the rail surface. The length or" the wheel will be greater than afigure obtained by multiplying the width of the railportion to be groundby the sine of the angle which the axis of the grinding wheel occupieswith respect to the rail, though only slightly greater than this figurewhen the grinding wheel is of relatively smal diameter and the convexity'of the rail not relatively great. The concavity of the grinding wheelsurface for a rail having the dimensionsgiven above, will be about onethirty-second of an inch in about nine inches, presuming the wheel to bedisposed Wltli'itS axis at an angle of about 18 to the rail. For 6X-treme accuracy the contour of the wheel can be calculated, or drawn,with exactitude; but approximate accuracy of the curvature of the railis all that is necessary in the grinding of tract; rails according to mymethod, and this is obtainable without diificult calculations ordrafting when the grinding wheel is of relatively small diameter, suchas about seven inches, and the convexity of the rail surface isiii-considerable.

My improved method provides a smoother ground surface for the rail thanwould otherwise be obtainable; because line of relative movement betweenthe rail and the wheel is inclined, not parallel, with respect to thelines of movement of the particles of abrasive which make up the wheel.Further, the speeds at which grinding wheels can be safely rotated arelimited and the operating speed is limited accordingly; but by myimproved method longer grinding out can be taken on a rail ofpredetermined width, with a corresponding increase of operating speed.With'the wheel disposed at 18 the speed of operation is about trebled,and at about doubled, over what would be practicable with the wheeldisposed in the old Way at right angles with the rail.

By way of example, I have described the following, specification oneform of apparatus that can be employed in practicing my improved method,and shown the same in theaccornpanyingdrawings, in which 1 is aperspective view of my improved grinder in position on a railway track,parts being broken away; Fig. 2 is an enlarged side view of the grindingwheel; Fig. 8 is a plan view of a portion of a rail and a g 'indingwheel in grinding position thereon; 4 is a plan View of the apparatus 0i; Fig. 5 "is a sectional view taken on line V--V of Fig. 4; and Fig. 6is a perspective view 01' portions of railway rails with a welded jointtherebetween, and with a grinding wheel in position thereon.

A- rail grinder constructed in accordance with my invention comprises atruck 1, having axles 2 and 3 on which are four wheels 4 adapted foroperation upon a street railway track compris ing rails 5. The truck 1constitutes a carriage for a grinding wheel 6 and a motor '7 having adriving connection thereto by means of belt 8.

The motor 7 and the grinding wheel 6 are mounted in a rectangular frame9 that is mounted for horizontal pivotal movement in trunnions 10supported by a plate 11 connecting the axles 2 and 3. Between the sidemembers 12 of the frame 9, and at the forward ends th reof, is

,mounted means for supporting and regulating the position of thegrinding wheel 6 with respect. to the carriage upon which it is mounted.

The grinding wheel has a shaft 13 that is mounted in bearings 14 at thelower ends of the vertical arms 1501" a cast steel yoke 16. The latteris secured for vertical slidable movement in a box-like guide frame 1'?!consistin top 18, two vertical members 19 and a b Two straps 21extending over the front e the respect vertical arms 15 are each he dposition by a stud bolt 22 extending through a vertical slot 23 in thecorresponding arm 15 connected to the back 20. Each stud bolt 22 rcvidedwith a clamping nut by m ns or" oh the relatively slidable yoire 16 dthe guide ame i! may be rigidly locked together vent relativemovement'when the grind l1" wheel is operation.

The vertical position of the yolze 16 in the frame 17 is controlled by awheel 26 and a screw-threaded shaft 27 extending through a icnary nut 28in the top 18 of the ironic and connected its lower end to the yoke hefro c l? is pivotally mounted in the 9 by means of bolts 29 and is heldin position by stud bolts extending slots 81 in the side mem ers 12 andd to members 19. Each of these Will Z36 adjusted e position or" thegrinding wheel tapering out in removing a low by a cam mechanism compbar 33 having a pivoted connec '18 axe 3 which does not rotate.

f the bar 33 has a vertical pin r 38 that is adapted to be clamp emovable axle 2 by means of a bolt ejecting member 41 which extendsrollers l2 connected to the frame SIB-.611 rails 9. The

s pivot caused by the inclined groove in the cam 37, causes a gradualraising or lowering of th rear portion of the frame 9 and a lowering orraising of the grinding wheel 6, but in lesser amounts, as the frame isturned about its trunnions 10.

the ratio of vertical movement of wheel to the horizontal travel of maybe arranged as desired, pre ably provide tapering cut varying about 1inch in depth for a travel of about 3.2 inch s oi the carriage along thetrack.

position and inclination. of the grinding wheel 5 be adjusted by severalmechanisms including cer' a n of tlose previously described. Forexample, adjusting the horizontal angle the wheel, rrame 9 is rotated tothe deby means of the tru1- h are adjustably con: ected to tho seadjustments will, however, small and may be of the order of inevthegrinding wheel a distance of ion lid

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larity such as a projecting seam of a Welded joint exists in the rail 5beneath the grinding wheel 6 as shown in Figs. 1 and 6, and that it isdesired to remove it by means of the grinding wheel 6. The latter isadjusted by means of the adjusting mechanisms described above to extendat the proper angle to conform to the normal convex upper surface of therails and in such vertical position as to engage the rail at theirregularity desired to be removed.

The carriage 1 is then moved along the track for such distances as maybe desirable by means of a hand wheel 46 which is connected to the axle2 by means of a sprocket 47 and sprocket chain 48. Current for the motor7 may be supplied in any suitable manner, such, for example, as by meansof a conductor that is connected to the usual trolley wire, andconnected through a conductor 49 and a switch 50 mounted on the frame 9.The grinding wheel rotates about an axis that is slightly oblique to thelongitudinal axis of the rail and the upper surface of the rail isground to its normal convex form.

When the wheel approaches a portion of the rail with which it engages,the initial portion of the cut is along a line that is substantially atthe same angle as the axis of the grinder, and such cut extends over theconvex upper surface of rail. Accordingly, in the removal of any portionof the upper surface of the rail any irregularity that may be caused byexcessive grinding at any particular portion of its travel will notcause a transverse depression in the rail, or a transverse projection,but any such irregularity will be engaged so gradually by the car wheelsand will leave such irregularities so gradually that no rebound of thewheels will cause them to inflict any damage upon other portions of therails.

In the case of projections above the normal surface of the rail, such asthose at welded joints, the truck will be reciprocated by means of thehand wheel over the raised portions and the grinder will be operated toreduce the height thereof until the upper surface of the rails and thejoint are of normal height and form. When the grinding operation issubstantially finished a relatively slight cut may be taken at arelatively rapid rate over the surface being ground for the purpose ofinsuring that no irregularities remain as a result of the grindingoperation.

In removing corrugations or irregularities that extend below the normalsurface of the rail it will, of course, be necessary to reduce thatportion of the rail by grinding off the higher spots between thedepressions until the corrugated portions of the rail are substantiallylevel. It will be necessary to extend such depressed portion of the railsomewhat in order to provide a properly inclined surface to the normalsurface the rails.

When it is desired to provide a gradual incline for a low spot, the cammechanism for automatically varying the height of the grinding wheel isplaced in operation when the carriage is at an appropriate position bytightening the bolt 39. The operation of the carriage then automaticallyproduces a tapering cut. The direction of moves ment the carriage andthe movement of the bar 33 by the earn 3'? determine whether thegrinding wheel is raised or lowered, as will be readily understood.

In any case, however, the operation of the grinding wheel at an anglethat is only slightly oblique to the axis of the rail insures that anychange in the surface of the rail, such as may be caused by the normaloperation of the grinder, or because of any accidental irregularity,will not operate to cause hammer blows of the wheels because of thegradual transition of the wheels upon engaging and leaving suchirregularities.

It will be appreciated that in operating my improved grinder upon curvedrails, or upon portions of tracks that are in other than straight linesand in level portions, the angle of the grinding wheel 4 may be adjustedto suitably conform tothe curvature of the rails in order that thesurface appropriate to such portions of the track may be maintained.

Furthermore, it may be desirable to employ a wheel whose outer surfaceis substantially a true cylinder instead of having a concave surface ofthe character described above.

The preferred horizontal angle of the axis of the grinding wheel to thelongitudinal axis of the rail is about 18, but such angle maybe variedin accordance with the position or shape of the rail to be operated uponor in accordance with the relation of the contour of the outer portionof the grinding wheel to the shape of the upper surface of the rail.

It will be noted that the grinding wheel of my invention avoids thedefects of apparatus of this character in use heretofore in that it issubstantially impossible by accident or otherwise to causeirregularities in the rail that are transverse thereto and which operateto cause additional irregularities by reason of hammer blows caused bywheels passing thereover.

The foregoing and other advantages will be appreciated by those skilledin the art of grinders for railway rails.

I claim:

1. The method of eliminating substantially transverse irregularitiesoccurring in track-rails which includes engaging the track-rail with theperipheral face of a grinding wheel having its axis disposed obliquelyto a line extending transversely of the rail at right angles thereto,and effecting relative longitudinal movement between the track-rail andthe grinding wheel while maintaining the engagement and the obliquity ofthe grinding wheel, whereby any grinding depressions are disposedangularly to the lines of contact made with the track rail by car wheelsoperating thereon.

2. The method of eliminating substantially transverse irregularitiesoccurring in track-rails of predetermined convexity while maintainingsaid convexity, which includes engaging the track-rail with theperipheral face of a grinding wheel having its axis disposed obliquelyto a line extending transversely to the rail at right angles thereto andhaving its peripheral face of a longitudinal concave contourcorresponding with the predetermined convexity of the trackrail asmodified by the obliquity of the grinding wheel, and eiiecting relativelongitudinal movement between the track-rail and the grinding wheelwhile maintaining the engagement and the obliquity of the grindingwheel, whereby any grinding depressions are disposed angularly to i thelines of contact made with the track-rail by wheels operating thereonandthe predetermined convexity of the track-rail is maintained.

CYRIL A. FOX.

